* {
  /* 初始化 */
  margin: 0;
  padding: 0;
}
body {
  /* 100%窗口高度 */
  height: 100vh;
  /* 溢出隐藏 */
  overflow: hidden;
}
.container {
  /* 绝对定位 */
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url("../../images/views/space.webp") no-repeat;
  /* 把背景图像扩展至足够大，以使背景图像完全覆盖背景区域 */
  background-size: cover;
  /* 定位背景图像为正中间 */
  background-position-x: center;
  /* 执行动画：动画名称 时长 线性的 无限次播放 */
  animation: animateBg 5s linear infinite;
}
span {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 4px;
  height: 4px;
  background-color: #fff;
  border-radius: 50%;
  /* 发光效果 */
  box-shadow: 0 0 0 4px rgba(255, 255, 255, 0.1),
    0 0 0 8px rgba(255, 255, 255, 0.1), 0 0 20px rgba(255, 255, 255, 1);
  /* 执行动画 */
  animation: animate 3s linear infinite;
}
/* 拖尾效果 */
span::before {
  content: "";
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 300px;
  height: 3px;
  background: linear-gradient(90deg, #fff, transparent);
}
/* 接下来分别为每一个流星设置位置、动画延迟时间、动画时长 */
span:nth-child(1) {
  top: 0;
  right: 0;
  /* initial关键字用于设置CSS属性为它的默认值 */
  left: initial;
  /* 动画延迟时间 */
  animation-delay: 0s;
  /* 动画时长 */
  animation-duration: 1s;
}
span:nth-child(2) {
  top: 0;
  right: 80px;
  left: initial;
  animation-delay: 0.2s;
  animation-duration: 3s;
}
span:nth-child(3) {
  top: 80px;
  right: 0;
  left: initial;
  animation-delay: 0.4s;
  animation-duration: 2s;
}
span:nth-child(4) {
  top: 0;
  right: 180px;
  left: initial;
  animation-delay: 0.6s;
  animation-duration: 1.5s;
}
span:nth-child(5) {
  top: 0;
  right: 400px;
  left: initial;
  animation-delay: 0.8s;
  animation-duration: 2.5s;
}
span:nth-child(6) {
  top: 0;
  right: 600px;
  left: initial;
  animation-delay: 1s;
  animation-duration: 3s;
}
span:nth-child(7) {
  top: 300px;
  right: 0;
  left: initial;
  animation-delay: 1.2s;
  animation-duration: 1.75s;
}
span:nth-child(8) {
  top: 0;
  right: 700px;
  left: initial;
  animation-delay: 1.4s;
  animation-duration: 1.25s;
}
span:nth-child(9) {
  top: 0;
  right: 1000px;
  left: initial;
  animation-delay: 0.75s;
  animation-duration: 2.25s;
}
span:nth-child(10) {
  top: 0;
  right: 450px;
  left: initial;
  animation-delay: 2.75s;
  animation-duration: 2.25s;
}

/* 定义动画 */
/* 背景缩放动画 */
@keyframes animateBg {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.2);
  }
}
/* 流星划过动画 */
@keyframes animate {
  0% {
    transform: rotate(315deg) translateX(0);
    opacity: 1;
  }
  90% {
    opacity: 1;
  }
  100% {
    transform: rotate(315deg) translateX(-1000px);
    opacity: 0;
  }
}
